From a7a8999a33a328b38a2681c9163a5b598db4d5cb Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Mon, 15 Feb 2016 20:30:36 -0800
Subject: [PATCH] more lru cache.

---
 lib/bcoin/blockdb.js |   9 +--
 lib/bcoin/chaindb.js |   2 +-
 lib/bcoin/lru.js     | 136 ++++++++++++++++++++++++-------------------
 lib/bcoin/ramdisk.js |  16 +++++
 4 files changed, 97 insertions(+), 66 deletions(-)

diff --git a/lib/bcoin/blockdb.js b/lib/bcoin/blockdb.js
index 120bf8aa..41753c2f 100644
--- a/lib/bcoin/blockdb.js
+++ b/lib/bcoin/blockdb.js
@@ -414,10 +414,11 @@ BlockDB.prototype._getCoinsByAddress = function _getCoinsByAddress(address, call
     var parts = data.key.split('/').slice(3);
     var hash = parts[0];
     var index = +parts[1];
+    var id = hash + '/' + index;
     var record = self.parseOffset(data.value);
     pending++;
-    if (self.unspentCache.has(hash + '/' + index)) {
-      coins.push(self.unspentCache.get(hash + '/' + index));
+    if (self.unspentCache.has(id)) {
+      coins.push(self.unspentCache.get(id));
       pending--;
       if (done) {
         if (!pending)
@@ -446,7 +447,7 @@ BlockDB.prototype._getCoinsByAddress = function _getCoinsByAddress(address, call
           value: data.value,
           spent: false
         });
-        self.unspentCache.set(hash + '/' + index, coin);
+        self.unspentCache.set(id, coin);
         coins.push(coin);
       }
 
@@ -715,7 +716,7 @@ function BlockData(options) {
 BlockData.prototype._init = function _init() {
   if (!bcoin.fs) {
     utils.debug('`fs` module not available. Falling back to ramdisk.');
-    this.ramdisk = bcoin.ramdisk(new Buffer([]), 40 * 1024 * 1024);
+    this.ramdisk = new bcoin.ramdisk(40 * 1024 * 1024);
     return;
   }
 
diff --git a/lib/bcoin/chaindb.js b/lib/bcoin/chaindb.js
index f2a468b3..c3b6b702 100644
--- a/lib/bcoin/chaindb.js
+++ b/lib/bcoin/chaindb.js
@@ -58,7 +58,7 @@ function ChainDB(chain, options) {
 ChainDB.prototype._init = function _init() {
   if (!bcoin.fs) {
     utils.debug('`fs` module not available. Falling back to ramdisk.');
-    this.ramdisk = bcoin.ramdisk(new Buffer([]), 40 * 1024 * 1024);
+    this.ramdisk = new bcoin.ramdisk(40 * 1024 * 1024);
     return;
   }
 
diff --git a/lib/bcoin/lru.js b/lib/bcoin/lru.js
index 73825ec2..b50c300e 100644
--- a/lib/bcoin/lru.js
+++ b/lib/bcoin/lru.js
@@ -23,23 +23,31 @@ function LRU(maxSize) {
   this.tail = null;
 }
 
-LRU.prototype._getSize = function _getSize(value) {
-  if (value == null)
-    return 1;
+LRU.prototype._getSize = function _getSize(item) {
+  var keySize = item.key.length * 2;
 
-  if (typeof value === 'number')
-    return 4;
+  if (item.value == null)
+    return keySize + 1;
 
-  if (value._raw)
-    return value._raw.length;
+  if (typeof item.value === 'number')
+    return keySize + 4;
 
-  if (value.getSize)
-    return value.getSize();
+  if (item.value._raw)
+    return keySize + item.value._raw.length;
 
-  if (typeof value.length === 'number')
-    return value.length;
+  if (item.value.getSize)
+    return keySize + item.value.getSize();
 
-  return 1;
+  if (typeof item.value._size === 'number')
+    return keySize + item.value._size;
+
+  if (typeof item.value === 'string')
+    return keySize + item.value.length * 2;
+
+  if (typeof item.value.length === 'number')
+    return keySize + item.value.length;
+
+  return keySize + 1;
 };
 
 LRU.prototype._compact = function _compact() {
@@ -49,31 +57,21 @@ LRU.prototype._compact = function _compact() {
     return;
 
   for (item = this.head; item; item = item.next) {
-    // if (this.size <= this.maxSize / 2 | 0)
     if (this.size < this.maxSize)
       break;
-    this.size -= this._getSize(item.value);
-    delete this.data[item.key];
+    this.remove(item.key);
   }
-
-  if (!item) {
-    this.head = null;
-    this.tail = null;
-    return;
-  }
-
-  this.head = item;
-  item.prev = null;
 };
 
 LRU.prototype.set = function set(key, value) {
   var item = this.data[key];
+
   if (item) {
-    this.size -= this._getSize(item.value);
-    this.size += this._getSize(value);
+    this.size -= this._getSize(item);
     item.value = value;
-    this._remove(item);
-    this._append(item);
+    this.size += this._getSize(item);
+    this._removeList(item);
+    this._appendList(item);
     this._compact();
     return;
   }
@@ -82,22 +80,21 @@ LRU.prototype.set = function set(key, value) {
 
   this.data[key] = item;
 
-  this._append(item);
+  this._appendList(item);
 
-  this.size += this._getSize(value);
+  this.size += this._getSize(item);
 
   this._compact();
 };
 
 LRU.prototype.get = function get(key) {
   var item = this.data[key];
-  var prev, next, tail;
 
   if (!item)
     return;
 
-  this._remove(item);
-  this._append(item);
+  this._removeList(item);
+  this._appendList(item);
 
   return item.value;
 };
@@ -108,29 +105,28 @@ LRU.prototype.has = function get(key) {
 
 LRU.prototype.remove = function remove(key) {
   var item = this.data[key];
-  var prev, next;
 
   if (!item)
     return false;
 
-  this.size -= this._getSize(item.value);
+  this.size -= this._getSize(item);
 
   delete this.data[key];
 
-  this._remove(item);
+  this._removeList(item);
 
   return true;
 };
 
-LRU.prototype._prepend = function prepend(item) {
-  this._insert(null, item);
+LRU.prototype._prependList = function prependList(item) {
+  this._insertList(null, item);
 };
 
-LRU.prototype._append = function prepend(item) {
-  this._insert(this.tail, item);
+LRU.prototype._appendList = function appendList(item) {
+  this._insertList(this.tail, item);
 };
 
-LRU.prototype._insert = function insert(ref, item) {
+LRU.prototype._insertList = function insertList(ref, item) {
   assert(!item.next);
   assert(!item.prev);
   if (ref == null) {
@@ -151,18 +147,18 @@ LRU.prototype._insert = function insert(ref, item) {
     this.tail = item;
 };
 
-LRU.prototype._remove = function insert(item) {
+LRU.prototype._removeList = function removeList(item) {
   if (item.prev)
     item.prev.next = item.next;
 
   if (item.next)
     item.next.prev = item.prev;
 
-  if (this.head === item)
+  if (item === this.head)
     this.head = item.next;
 
-  if (this.tail === item)
-    this.tail = item.prev;
+  if (item == this.tail)
+    this.tail = item.prev || this.head;
 
   item.prev = null;
   item.next = null;
@@ -188,44 +184,62 @@ var a2 = '2';
 var a3 = '3';
 var a4 = '4';
 var a5 = '5';
-var lru = new LRU(5);
+var a6 = '6';
+var lru = new LRU(((2 * 4) + 4) * 2);
 lru.set('a1', a1);
 assert(lru.get('a1') === '1');
-assert(lru.size === 1);
+assert(lru.size === ((2 * 1) + 1) * 2);
 assert(lru.head.key === 'a1' && lru.tail.key === 'a1' && !lru.head.prev && !lru.head.next);
-console.log(lru._keys());
+lru._keys();
+// console.log(lru._keys());
 lru.set('a2', a2);
 assert(lru.get('a2') === '2');
-assert(lru.size === 2);
+assert(lru.size === ((2 * 2) + 2) * 2);
 assert(lru.head.key === 'a1' && lru.tail.key === 'a2'
   && !lru.head.prev && lru.head.next.key === 'a2'
   && !lru.tail.next && lru.tail.prev.key === 'a1');
-console.log(lru._keys());
+lru._keys();
+// console.log(lru._keys());
 lru.set('a3', a3);
 assert(lru.get('a3') === '3');
-assert(lru.size === 3);
-console.log(lru._keys());
+assert(lru.size === ((2 * 3) + 3) * 2);
+lru._keys();
+// console.log(lru._keys());
 lru.set('a3', a3);
 assert(lru.get('a3') === '3');
-assert(lru.size === 3);
-console.log(lru._keys());
+assert(lru.size === ((2 * 3) + 3) * 2);
+lru._keys();
+// console.log(lru._keys());
 lru.set('a4', a4);
 assert(lru.get('a4') === '4');
-assert(lru.size === 4);
-console.log(lru._keys());
-// lru.set('a5', a5);
-// assert(lru.get('a5') === '5');
-// assert(lru.size === 4);
-// assert(!lru.get('a1'));
+assert(lru.size === ((2 * 4) + 4) * 2);
+lru._keys();
+// console.log(lru._keys());
 assert(lru.get('a1'));
 lru.remove('a1');
-console.log(lru._keys());
+lru._keys();
+// console.log(lru._keys());
 var _a3 = lru.head.next;
 assert(_a3.key === 'a3');
 assert(_a3.prev === lru.head && _a3.next === lru.tail);
 assert(lru.head.key === 'a2' && lru.tail.key === 'a4'
   && !lru.head.prev && lru.head.next.key === 'a3'
   && !lru.tail.next && lru.tail.prev.key === 'a3');
+lru.set('a5', a5);
+assert(lru.get('a5') === '5');
+assert(lru.size === ((2 * 4) + 4) * 2);
+assert(!lru.get('a1'));
+lru._keys();
+// console.log(lru._keys());
+lru.get('a2');
+lru._keys();
+// console.log(lru._keys());
+lru.set('a6', a6);
+assert(lru.get('a6') === '6');
+assert(lru.size === ((2 * 4) + 4) * 2);
+assert(!lru.get('a3'));
+lru._keys();
+// console.log(lru._keys());
 
 /**
  * Expose
diff --git a/lib/bcoin/ramdisk.js b/lib/bcoin/ramdisk.js
index 10415a9f..d35d9c7d 100644
--- a/lib/bcoin/ramdisk.js
+++ b/lib/bcoin/ramdisk.js
@@ -4,10 +4,26 @@
  * https://github.com/indutny/bcoin
  */
 
+var bcoin = require('../bcoin');
+var utils = bcoin.utils;
+var assert = utils.assert;
+
+/**
+ * Ramdisk
+ */
+
 function Ramdisk(fileData, size) {
   if (!(this instanceof Ramdisk))
     return new Ramdisk(fileData, size);
 
+  if (size == null) {
+    size = fileData;
+    fileData = new Buffer([]);
+  }
+
+  assert(Buffer.isBuffer(fileData));
+  assert(typeof size === 'number');
+
   if (size < fileData.length)
     size = fileData.length + (fileData.length / 2 | 0);